How to add "Tracking Number Required" box to process screen

1. Enable “Allow changing postage information on order process screen” in Settings > Postal Service Methods > Postage settings - this function is needed if user wants to make changes in postage and packaging details.

2. Set the postal service as "Tracking Number Required" in Postal Service Methods > Postal Service. 

3. Now you are able to enter tracking number if this postal service is selected.

If you forget to enter tracking number in the field, the system will remind you that this service require tracking number.